Bachmann, 55, rates the strongest with very conservative caucusgoers, along with those who are well-educated and ages 45 to 64.

More respondents pick her as their second choice, 18 percent, than name Romney, 10 percent.

“Michele Bachmann has always looked like a fit for Iowa on paper, and the debate likely helped solidify her standing,” pollster J. Ann Selzer said. “This poll confirms she has potential to do very well here.”

When it comes to popularity, Bachmann, a religious conservative, is in a different league from the other candidates. She has very low unfavorables at 12 percent. Only Texas Gov. Rick Perry, not a declared candidate yet, is lower at 8 percent.

Selzer said: “I don’t know that this will last. There’s a long road to go between now and February.”

Bachmann has spent eight days in Iowa so far this year and returns tonight for a “welcome home” event and formal campaign announcement Monday in Waterloo that will highlight her Iowa roots.

Gingrich, 68, has the highest unfavorable rating of the eight declared candidates in the poll’s trial heat.

Gingrich, who was the key face of Republican opposition to Democrats during former President Bill Clinton’s administration, is sometimes seen as divisive. He made headlines recently for using the word “radical” to describe U.S. Rep. Paul Ryan’s plan to privatize Medicare.

Forty-six percent of respondents have a good impression of him, while 43 percent view him unfavorably.

Observers have questioned his campaign’s future after most of his Iowa and national campaign staff resigned en masse.

Huntsman, 51, a relatively moderate Republican, finished at the bottom of the poll. Two percent consider him their first choice, and 2 percent pick him as second choice.

Huntsman, who lives in Washington, D.C., after resigning from his post as President Barack Obama’s ambassador to China, has said he won’t compete in Iowa, citing his opposition to ethanol subsidies. He intends to make his first visit to the state for an Aug. 11 debate.

Only 22 percent view him favorably, compared to 19 percent unfavorably. Fifty-nine percent don’t know him well enough to have an opinion of him.

Paul, 75, is running for president for the third time and is pushing back against lingering perceptions that he’s a fringe candidate. He’s viewed favorably by 53 percent of respondents. Thirty-two percent view him unfavorably.

While 7 percent say Paul is their top choice for president, he’s also second choice for 12 percent.

Paul advocates limited constitutional government, low taxes, free markets and a return to monetary policies based on commodity-backed currency. Paul spent more than any other candidate to snag the most prominent tent spot at the Aug. 13 straw poll in Ames.

National commentators often cast Pawlenty’s best strategy as angling to become the alternative to Mitt Romney as the favorite of establishment Republicans. But even if Romney decides not to compete for the Iowa caucuses at all, Pawlenty, 50, doesn’t benefit much.

Among those who pick Romney as their first choice, only 15 percent choose Pawlenty as their second choice. Bachmann would get 26 percent of that Romney vote.

There are bright spots for Pawlenty: People don’t dislike him, despite perceptions of a milquetoast performance in the New Hampshire debate. Just 13 percent have an unfavorable impression of him. And while 6 percent say Pawlenty is their top choice, which is in line with national poll numbers, 12 percent name him their backup pick.

“(Indiana Gov.) Mitch Daniels’ exit gave them a really big window, but that window’s going to start to close,” said Jennifer Duffy of Cook Political Report. “My guess is that he needs to turn this around by Labor Day, or I’m not sure how viable he is in the long term. If Pawlenty is not viable in Iowa, then it’s hard to make the argument that he’s viable for the nomination.”

Predictably, Romney, 64, who is pitching economic recovery as his forte, does better with more moderate respondents. He wins with those with less than a college education (24 percent to Bachmann’s 16 percent) and those who earn less than $50,000 a year (29 percent to 16 percent).

Fifty-two percent of respondents have a favorable impression of Romney, but 38 percent view him unfavorably.

That impression will be “impossible to shake,” said Jennifer Duffy of the Cook Political Report.

Nationally among Republicans, 59 percent hold a favorable view of Romney, and 16 percent view him negatively, according to a Bloomberg National Poll released last week.

Religious conservatives stalled his campaign here four years ago. He has set foot in Iowa only once this year.

Santorum, 53, a religious conservative who leads candidates with the 29 days he’s visited Iowa this cycle, has yet to build a strong base here: 45 percent don’t know him well enough to have an opinion about him. Thirty-eight percent view him favorably, and 17 percent unfavorably.

Iowa is expected to be his strongest early state, so he’s got to do well here, analysts say.